A typical display device is provided with a source driver for driving source bus lines (video signal lines) and a gate driver for driving gate bus lines (scanning signal lines). These drivers are provided with a plurality of output terminals to be connected to a plurality of lines (source bus lines or gate bus lines) in a display unit in accordance with a versatile resolution. From the output terminals of the source driver, video signals for an image to be displayed are outputted. From the output terminals of the gate driver, scanning signals for writing video signals to pixel capacitances line by line are outputted. It should be noted that there have conventionally been many cases in which the driver that functionally constitutes a single component of a display device is configured by a plurality of semiconductor chips.
In the meantime, in recent years, there is a case in which a panel having a resolution different from versatile resolutions (hereinafter referred to as a “specially-shaped panel”) is employed for a display device. When a normal driver is used to drive such a specially-shaped panel, the number of lines (e.g., source bus lines) provided within a display unit may not match the number of output terminals provided within a driver (e.g., a source driver), and a surplus may be resulted from an output from the driver. For example, a case is considered in which an SVGA-type (number of pixels: 800×600) liquid crystal panel is driven using two source driving IC chips SD1, SD2 each having 960 output terminals as illustrated in FIG. 25. In a case of an RGB color display device, a single pixel is configured by three sub-pixels including R (red), G (green), and B (blue), and thus the number of source bus lines is (600×3=) 1800. Here, as for the source driving IC chip SD1, 960 output terminals are connected respectively to source bus lines SL1-SL960 within the display unit. In contrast, as for the source driving IC chip SD2, although 840 output terminals are connected respectively to the source bus lines SL961-SL1800 within the display unit, the remaining 120 output terminals are not connected to the source bus lines within the display unit (see a reference number 9 in FIG. 25). Therefore, outputs from these 120 output terminals may not contribute to display of an image. Hereinafter, such outputs are referred to as “surplus outputs”.
The above drivers (the source driver and the gate driver) include shift registers. For example, in the source driver, sampling (acquisition) of the video signals transmitted to the source driver from a timing controller and such is performed by sampling pulses sequentially outputted from respective stages of a shift register. Then, an image is displayed in the display unit by driving each of the source bus lines based on the sampled video signals. In the meantime, there is also a driver that employs a bidirectional shift register, since a mode of implementation of the driver (IC chip) to the panel is not uniform. In a display device provided with such a driver, depending on the mode of implementation of the driver, a shifting direction of data in the shift register is made opposite to a regular direction (forward direction). This allows sampling of data within the driver in an order opposite to the regular order.
Regarding the present invention, there have been known the following conventional techniques. According to the invention disclosed in Japanese Patent Application Laid-Open No. 2005-4120, by providing a line memory in a timing controller, it is possible to change an order of display data transmitted to a source driver from the timing controller. According to the invention disclosed in Japanese Patent Application Laid-Open No. 2005-181982, by operating the source drivers separately in two groups, it is possible to operate the display device even when a horizontal blanking interval is 0 in the case in which surplus outputs are produced in the source drivers.